Chris, maybe my explanation was unclear. OF COURSE the fins bend, that is the whole point of the Miragedrive, but you DON'T sail sideways; almost all the time, the Island is going just about straight ahead as far as the water is concerned (unlike the wind). When you pedal, you force the fins to go sideways in the water, and the flex in the fins generates forward force. If you stop pedaling, the only possible force able to flex the fins is leeway, which is minimised by the centreboard/daggerboard plus the narrow hull and amas, which will all resist sideways motion. At that point, the flexible part of the fins, being flexible, will NOT offer any resistance to the relatively minute leeway. Sure, at the very top of the fin, movement is slightly restricted, but even here, the "slop" available would come very close to equaling the angle of leeway, so even up there, sideways resistance would be minimal
Waving a miragedrive sideways in the water obviously bears no relationship to its behaviour when just hanging down under the hull
Sorry, but the laws of physics cannot be overcome.
2012 Tandem Island "SIC EM" with Hobie spinnaker!
Last edited by tonystott on Tue Jul 24, 2012 8:31 pm, edited 1 time in total.